In recent years, large-size screens are often used in concerts or events for visual effects. In typical cases, a multidisplay apparatus that allows a plurality of image display apparatuses to display a plurality of images side by side on a screen is used.
Such a multidisplay apparatus is required to assure the continuity of the plurality of images so that viewers do not feel a sense of inconsistency between the displayed images. Normal image display apparatuses have a function to adjust the brightness, white balance, hue, saturation or the like of the displayed images. Conventional techniques adjust any of the above characteristics as necessary to uniform the color reproduction in the displayed images and assure the continuity of the plurality of adjacent images (hereinafter referred to as “color continuity”).
However, the above method for adjusting the brightness, white balance, hue, saturation is not enough to obtain the perfect continuity of the images on the screen. This is because variations inevitably result among display devices and other optical devices such as the liquid crystal display devices, color prisms, color filters, lamps, phosphors or the like in the plurality of image display apparatuses, in terms of the color reproduction, luminescence characteristics, transmission characteristics or the like. This results in difference in the chromaticity between the images, rendering the displayed images discontinuous, and giving the audience an impression of a patchwork.
Conventionally, there is only one technique to solve the above problem. In this technique, image display apparatuses that display such images as have close chromaticity values to each other are selected among a plurality of image display apparatuses, and the selected apparatuses are arranged to be adjacent to each other. However, there is no guarantee that the plurality of image display apparatuses include such apparatuses providing similar chromaticity values, and even if they include, the chromaticity values do not perfectly match. This has kept the above-stated problem that the discontinuity of the images in color reproduction arises and impairs the unity of the images as a whole, unsolved.
It is therefore the object of the present invention to provide an image signal processing apparatus for achieving the unity of the displayed images as a whole by allowing a plurality of displayed images to have substantially the same chromaticity, an image display apparatus containing the image signal processing apparatus, a multidisplay apparatus, and a chromaticity adjustment method for use in the multidisplay apparatus.